Characterization of polar stratospheric cloud (PSC) using ground-based Fourier-transform infrared spectrometer (FTIR) at Syowa Station, Antarctica

Abstract

Polar stratospheric clouds (PSCs) play an important role in ozone destruction via the occurrence of heterogeneous reactions on their surface that convert reservoir species of active chlorine and bromine (e.g., HCl, ClONO_2, HBr, or BrONO_2) into active Cl_2 or Br_2. However, a lack of direct measurements means that uncertainty remains regarding the characteristics, types, mixtures, and nature of PSCs. To address this problem, we conducted, for the first time, ground-based measurements of the features of PSCs using a low-resolution Fourier-transform infrared (FTIR) spectrometer at Syowa Station, Antarctica, in 2007. Many PSCs were observed between July and August 2007. We succeeded in identifying the features of Ice (Type-II), NAD and or β-NAT (Type-Ia), and STS (Type-Ib) PSCs in the zenith sky infrared spectra measured by FTIR.